Querydsl and QBE nest into single argument input type

Closes gh-216

Author: rstoyanchev

spring-graphql-docs/src/docs/asciidoc/index.adoc

@@ -865,9 +865,11 @@ Then use it to create a `DataFetcher`:
 You can now register the above `DataFetcher` through a
 <<execution.graphqlsource.runtimewiring-configurer>>.
 
-The `DataFetcher` builds a Querydsl `Predicate` from GraphQL request parameters, and
-uses it to fetch data. Spring Data supports `QuerydslPredicateExecutor` for JPA,
-MongoDB, and LDAP.
+The `DataFetcher` builds a Querydsl `Predicate` from GraphQL arguments, and uses it to
+fetch data. Spring Data supports `QuerydslPredicateExecutor` for JPA, MongoDB, and LDAP.
+
+NOTE: For a single argument that is a GraphQL input type, `QuerydslDataFetcher` nests one
+level down, and uses the values from the argument sub-map.
 
 If the repository is `ReactiveQuerydslPredicateExecutor`, the builder returns
 `DataFetcher<Mono<Account>>` or `DataFetcher<Flux<Account>>`. Spring Data supports this
@@ -1058,6 +1060,9 @@ The `DataFetcher` uses the GraphQL arguments map to create the domain type of th
 repository and use that as the example object to fetch data with. Spring Data supports
 `QueryByExampleDataFetcher` for JPA, MongoDB, Neo4j, and Redis.
 
+NOTE: For a single argument that is a GraphQL input type, `QueryByExampleDataFetcher`
+nests one level down, and binds with the values from the argument sub-map.
+
 If the repository is `ReactiveQueryByExampleExecutor`, the builder returns
 `DataFetcher<Mono<Account>>` or `DataFetcher<Flux<Account>>`. Spring Data supports this
 variant for MongoDB, Neo4j, Redis, and R2dbc.

spring-graphql/src/main/java/org/springframework/graphql/data/query/QueryByExampleDataFetcher.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,6 +26,7 @@
 import graphql.schema.DataFetcher;
 import graphql.schema.DataFetchingEnvironment;
 import graphql.schema.DataFetchingFieldSelectionSet;
+import graphql.schema.GraphQLArgument;
 import graphql.schema.GraphQLTypeVisitor;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -41,8 +42,9 @@
 import org.springframework.data.util.TypeInformation;
 import org.springframework.graphql.data.GraphQlArgumentBinder;
 import org.springframework.graphql.data.GraphQlRepository;
-import org.springframework.graphql.execution.SelfDescribingDataFetcher;
 import org.springframework.graphql.execution.RuntimeWiringConfigurer;
+import org.springframework.graphql.execution.SelfDescribingDataFetcher;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.validation.BindException;
 
@@ -108,13 +110,32 @@ public abstract class QueryByExampleDataFetcher<T> {
 
 	/**
 	 * Prepare an {@link Example} from GraphQL request arguments.
-	 * @param env contextual info for the GraphQL request
+	 * @param environment contextual info for the GraphQL request
 	 * @return the resulting example
 	 */
 	@SuppressWarnings({"ConstantConditions", "unchecked"})
-	protected Example<T> buildExample(DataFetchingEnvironment env) throws BindException {
+	protected Example<T> buildExample(DataFetchingEnvironment environment) throws BindException {
+		String name = getArgumentName(environment);
 		ResolvableType targetType = ResolvableType.forClass(this.domainType.getType());
-		return (Example<T>) Example.of(this.argumentBinder.bind(env, null, targetType));
+		return (Example<T>) Example.of(this.argumentBinder.bind(environment, name, targetType));
+	}
+
+	/**
+	 * For a single argument that is a GraphQL input type, return the argument
+	 * name, thereby nesting and having the example Object populated from the
+	 * sub-map. Otherwise, {@code null} to bind using the top-level map.
+	 */
+	@Nullable
+	private static String getArgumentName(DataFetchingEnvironment environment) {
+		Map<String, Object> arguments = environment.getArguments();
+		List<GraphQLArgument> definedArguments = environment.getFieldDefinition().getArguments();
+		if (definedArguments.size() == 1) {
+			String name = definedArguments.get(0).getName();
+			if (arguments.get(name) instanceof Map<?,?>) {
+				return name;
+			}
+		}
+		return null;
 	}
 
 	protected boolean requiresProjection(Class<?> resultType) {

spring-graphql/src/main/java/org/springframework/graphql/data/query/QuerydslDataFetcher.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -47,8 +47,8 @@
 import org.springframework.data.repository.query.FluentQuery.FetchableFluentQuery;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.graphql.data.GraphQlRepository;
-import org.springframework.graphql.execution.SelfDescribingDataFetcher;
 import org.springframework.graphql.execution.RuntimeWiringConfigurer;
+import org.springframework.graphql.execution.SelfDescribingDataFetcher;
 import org.springframework.util.Assert;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
@@ -134,7 +134,7 @@ protected Predicate buildPredicate(DataFetchingEnvironment environment) {
 		EntityPath<?> path = SimpleEntityPathResolver.INSTANCE.createPath(this.domainType.getType());
 		this.customizer.customize(bindings, path);
 
-		for (Map.Entry<String, Object> entry : environment.getArguments().entrySet()) {
+		for (Map.Entry<String, Object> entry : getArgumentValues(environment).entrySet()) {
 			Object value = entry.getValue();
 			List<Object> values = (value instanceof List ? (List<Object>) value : Collections.singletonList(value));
 			parameters.put(entry.getKey(), values);
@@ -143,6 +143,23 @@ protected Predicate buildPredicate(DataFetchingEnvironment environment) {
 		return BUILDER.getPredicate(this.domainType, parameters, bindings);
 	}
 
+	/**
+	 * For a single argument that is a GraphQL input type, return the sub-map
+	 * under the argument name, or otherwise the top-level argument map.
+	 */
+	@SuppressWarnings("unchecked")
+	private static Map<String, Object> getArgumentValues(DataFetchingEnvironment environment) {
+		Map<String, Object> arguments = environment.getArguments();
+		if (environment.getFieldDefinition().getArguments().size() == 1) {
+			String name = environment.getFieldDefinition().getArguments().get(0).getName();
+			Object value = arguments.get(name);
+			if (value instanceof Map<?,?>) {
+				return (Map<String, Object>) value;
+			}
+		}
+		return arguments;
+	}
+
 	protected boolean requiresProjection(Class<?> resultType) {
 		return !resultType.equals(this.domainType.getType());
 	}

spring-graphql/src/test/java/org/springframework/graphql/ResponseHelper.java

@@ -106,7 +106,7 @@ public <T> T rawValue(String path) {
 
 	private void assertNoErrors() {
 		if (!this.errorsChecked) {
-			assertThat(this.errors).as("Errors present in GraphQL response").isEmpty();
+			assertThat(this.errors).as("GraphQL response errors: " + this.errors).isEmpty();
 			this.errorsChecked = true;
 		}
 	}

spring-graphql/src/test/java/org/springframework/graphql/data/query/QuerydslDataFetcherTests.java

@@ -44,6 +44,7 @@
 import org.springframework.data.repository.Repository;
 import org.springframework.graphql.Author;
 import org.springframework.graphql.BookSource;
+import org.springframework.graphql.ExecutionGraphQlResponse;
 import org.springframework.graphql.GraphQlSetup;
 import org.springframework.graphql.ResponseHelper;
 import org.springframework.graphql.data.GraphQlRepository;
@@ -74,7 +75,7 @@ class QuerydslDataFetcherTests {
 
 
 	@Test
-	void shouldFetchSingleItems() {
+	void shouldFetchSingleItem() {
 		Book book = new Book(42L, "Hitchhiker's Guide to the Galaxy", new Author(0L, "Douglas", "Adams"));
 		mockRepository.save(book);
 
@@ -277,6 +278,25 @@ void shouldReactivelyFetchMultipleItems() {
 		tester.accept(graphQlSetup(mockRepository));
 	}
 
+	@Test
+	void shouldNestForSingleArgumentInputType() {
+		Book book1 = new Book(42L, "Hitchhiker's Guide to the Galaxy", new Author(0L, "Douglas", "Adams"));
+		Book book2 = new Book(53L, "Breaking Bad", new Author(0L, "", "Heisenberg"));
+		mockRepository.saveAll(Arrays.asList(book1, book2));
+
+		String queryName = "booksByCriteria";
+
+		Mono<ExecutionGraphQlResponse> responseMono =
+				graphQlSetup(queryName, QuerydslDataFetcher.builder(mockRepository).many())
+						.toGraphQlService()
+						.execute(request("{" + queryName + "(criteria: {id: 42}) {name}}"));
+
+		List<Book> books = ResponseHelper.forResponse(responseMono).toList(queryName, Book.class);
+
+		assertThat(books).hasSize(1);
+		assertThat(books.get(0).getName()).isEqualTo(book1.getName());
+	}
+
 	static GraphQlSetup graphQlSetup(String fieldName, DataFetcher<?> fetcher) {
 		return initGraphQlSetup(null, null).queryFetcher(fieldName, fetcher);
 	}

spring-graphql/src/test/java/org/springframework/graphql/data/query/jpa/QueryByExampleDataFetcherJpaTests.java

@@ -38,6 +38,7 @@
 import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
 import org.springframework.data.repository.query.QueryByExampleExecutor;
 import org.springframework.graphql.BookSource;
+import org.springframework.graphql.ExecutionGraphQlResponse;
 import org.springframework.graphql.GraphQlSetup;
 import org.springframework.graphql.ResponseHelper;
 import org.springframework.graphql.data.query.QueryByExampleDataFetcher;
@@ -169,6 +170,25 @@ void shouldFetchSingleItemsWithDtoProjection() {
 		assertThat(actualBook.getName()).isEqualTo("The book is: Hitchhiker's Guide to the Galaxy");
 	}
 
+	@Test
+	void shouldNestForSingleArgumentInputType() {
+		Book book1 = new Book(42L, "Hitchhiker's Guide to the Galaxy", new Author(0L, "Douglas", "Adams"));
+		Book book2 = new Book(53L, "Breaking Bad", new Author(0L, "", "Heisenberg"));
+		repository.saveAll(Arrays.asList(book1, book2));
+
+		String queryName = "booksByCriteria";
+
+		Mono<ExecutionGraphQlResponse> responseMono =
+				graphQlSetup(queryName, QueryByExampleDataFetcher.builder(repository).many())
+						.toGraphQlService()
+						.execute(request("{" + queryName + "(criteria: {id: 42}) {name}}"));
+
+		List<Book> books = ResponseHelper.forResponse(responseMono).toList(queryName, Book.class);
+
+		assertThat(books).hasSize(1);
+		assertThat(books.get(0).getName()).isEqualTo(book1.getName());
+	}
+
 	private static GraphQlSetup graphQlSetup(String fieldName, DataFetcher<?> fetcher) {
 		return initGraphQlSetup(null).queryFetcher(fieldName, fetcher);
 	}